Riyadh, Nov. 6 -- In a gripping winner-takes-all clash that stretched over two hours and 36 minutes, No. 4 seed Amanda Anisimova delivered one of her biggest wins of the season, defeating No. 2 seed Iga Swiatek in the WTA Finals at the King Saud University Indoor Arena.

According to Olympics.com, after dropping a tight first set 6-7 (3), Anisimova stormed back to win 6-4, 6-2 - a gutsy performance that not only sent her into the semifinals, but also handed Swiatek a rare piece of history: it's the first time she's lost back-to-back matches after winning the opening set.

Anismova, currently enjoying a career-high ranking, will next face Elena Rybakina, who has been in commanding form throughout the tournament.

The Wimbledon champion toppe...